Bug 11222: fix crash that can occur in search for items to add to label batch

Bug 11222: fix crash that can occur in search for items to add to label batch

This patch fixes a regression on label-item-search.pl introduced by
the patch for bug 9239 where searching for items to add to a label
batch fails with an error if QueryParser is not enabled and you use
the "Added on or before date" search option.

Test plan:

0) Set "UseQueryParser" to "do not try"
1) Start with an installation with bibliografic data and items
   information.
2) Check that in items there are values inside Accession Date

Without the patch:
a) Go in Home› Tools› Labels  and click on 'New batch'
b) Click on 'Add Item(s)'
c) Try to select items with option "Added on or before date"
d) You will receive an error

With the patch:
Try steps a),b), and c)
Now you don't receive an error and you can select items

Signed-off-by: Owen Leonard <oleonard@myacpl.org>
Added a description of the problem and copied the test plan from the bug
report, with the addition of the information that QueryParser must be
off to confirm and test.

Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
Signed-off-by: Galen Charlton <gmc@esilibrary.com>
(cherry picked from commit 69c42067ced1da3821e8a893c76c2f1f1195f946)
Signed-off-by: Fridolin SOMERS <fridolin.somers@biblibre.com>